Check Signal Attributes

Error when input signal does or does not match selected attributes exactly

Library

Signal Management / Signal Attributes

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Description

The Check Signal Attributes block terminates the simulation with an error when the input characteristics differ from the characteristics you specify in the block parameters.

When you set Error when input to Does not match attributes exactly, the block generates an error when the input fails to match any of the specified attributes. Only signals that possess all of the specified attributes propagate to the output unaltered and do not cause the block to generate an error.

When you set Error when input to Matches attributes exactly, the block generates an error only when the input possesses all specified attributes. Signals that do not possess all of the specified attributes propagate to the output unaltered, and do not cause the block to generate an error.

Signal Attributes

The Check Signal Attributes block can test for up to five different signal attributes, as specified by the following parameters. When you select Ignore for any parameter, the block does not check the signal for the corresponding attribute. For example, when you set Complexity to Ignore, neither real nor complex inputs cause the block to generate an error. The attributes are:

• Complexity

  Check whether the input is real or complex. You can display this information in a model by attaching a Probe block with Probe complex signal selected. Alternatively, in the Debug tab, select Information Overlays > Port Data Type.

• Dimensionality

  Check the dimensionality of the input for compliance or noncompliance with the attributes in the subordinate Dimension menu. See the following table. M and N are positive integers unless otherwise indicated.

  Dimensions	Is...	Is not...
  1-D	1-D vector, 1-D scalar	M-by-N matrix, 1-by-N matrix (row vector), M-by-1 matrix (column vector), 1-by-1 matrix (2-D scalar)
  2-D	M-by-N matrix, 1-by-N matrix (row vector), M-by-1 matrix (column vector), 1-by-1 matrix (2-D scalar)	1-D vector, 1-D scalar
  Scalar (1-D or 2-D)	1-D scalar, 1-by-1 matrix (2-D scalar)	1-D vector with length>1, M-by-N matrix with M>1 and/or N>1
  Vector (1-D or 2-D)	1-D vector, 1-D scalar, 1-by-N matrix (row vector), M-by-1 matrix (column vector), 1-by-1 matrix (2-D scalar) Vector (1-D or 2-D) or scalar	M-by-N matrix with M>1 and N>1
  Row Vector (2-D)	1-by-N matrix (row vector), 1-by-1 matrix (2-D scalar) Row vector (2-D) or scalar	1-D vector, 1-D scalar, M-by-N matrix with M>1
  Column Vector (2-D)	M-by-1 matrix (column vector), 1-by-1 matrix (2-D scalar) Column vector (2-D) or scalar	1-D vector, 1-D scalar, M-by-N matrix with N>1
  Full matrix	M-by-N matrix with M>1 and N>1	1-D vector, 1-D scalar, 1-by-N matrix (row vector), M-by-1 matrix (column vector), 1-by-1 matrix (2-D scalar)
  Square matrix	M-by-N matrix with M=N, 1-D scalar, 1-by-1 matrix (2-D scalar	M-by-N matrix with M≠N, 1-D vector, 1-by-N matrix (row vector), M-by-1 matrix (column vector)

  In the Debug tab, when you select Information Overlays > Signal Dimensions, Simulink^® displays the size of a 1-D vector signal as an unbracketed integer, and displays the dimension of a 2-D signal as a pair of bracketed integers, [MxN]. Simulink does not display any size information for a 1-D or 2-D scalar signal. You can also display dimension information for a signal in a model by attaching a Probe block with Probe signal dimensions selected.

• Data type

  Check the signal data type for compliance (Is...) or noncompliance (Is not...) with the attributes in the subordinate General data type menu. See the following table. You can individually select any of the specific data types listed in the (Is...) column from the subordinate Specific data type menu.

  General Data Type	Is...	Is not...
  Boolean	boolean	single, double, uint8, int8, uint16, int16, uint32, int32, fixed point, enumerated
  Enumerated	A user-defined enumerated data type. See Data Types (Simulink).	boolean, single, double, uint8, int8, uint16, int16, uint32, int32, fixed point
  Floating point	single, double	boolean, uint8, int8, uint16, int16, uint32, int32, fixed point, enumerated
  Floating point or Boolean	single, double, boolean	uint8, int8, uint16, int16, uint32, int32, fixed point, enumerated
  Fixed point	fixed point, uint8, int8, uint16, int16, uint32, int32	boolean, single, double, enumerated
  Integer	Signed integer int8, int16, int32 Unsigned integer uint8, uint16, uint32	boolean, single, double, fixed point, enumerated

  To display data type information, in the Debug tab, select Information Overlays > Port Data Type.

• Sample time

  Check whether the signal is discrete time or continuous time. In the Debug tab, when you select Information Overlays > Colors, Simulink displays continuous-time signal lines in black or grey and discrete-time signal lines in colors corresponding to the relative rate.

  When you attach a Probe block with Probe sample time enabled to a continuous-time signal, the block icon displays Ts:[0 To], where To is the sample time offset. Valid values of To for continuous-time signals are 0 and 1. When To is 0, updates occur at every major and minor time step. When To is 1, updates occur only at major time steps and the sample time is fixed in minor time step.

  When you attach a Probe block with Probe sample time enabled to a discrete-time signal, the block icon displays Ts:[Ts To] for sample-based signals, and Tf:[Tf To] for frame-based signals. Ts and Tf are the positive sample period and frame period, respectively. To is the offset, such that 0 ≤ offset < period. Frame-based signals are almost always discrete time.

Parameters

Error when input

Specify whether the block generates an error when the input does or does not possess all of the required attributes.

Complexity

Specify the complexity for which you want to check the input, Real or Complex. When you select Ignore from the list, the block does not check the complexity of the input.

Dimensionality

Specify whether you want to check the input for compliance or noncompliance with the attributes in the subordinate Dimensions menu. When you select Ignore from the list, the block does not check the dimensionality of the input.

Dimensions

Specify the dimensions for which you want to check the input. This parameter is only visible when you set the Dimensionality parameter to Is... or Is not....

Data type

Specifies whether you want to check the input for compliance or noncompliance with the attributes in the subordinate General data type menu. When you select Ignore from the list, the block does not check the input data type.

General data type

Specify the general data type for which you want to check the input. This parameter is only visible when you set the Data type to Is... or Is not....

Specific floating-point

Specify the floating-point data type for which you want to check the input. This parameter is only visible when you set the General data type to Floating-point or Floating-point or boolean.

Specific fixed-point

Specify the fixed-point data type for which you want to check the input. This parameter is only visible when you set the General data type to Fixed-point.

Specific integer

Specify the integer data type for which you want to check the input. This parameter is only visible when you set the General data type to Integer.

Sample time

Specify the sample time for which you want to check the input, Discrete or Continuous. When you select Ignore from the list, the block does not check the sample time of the input.

Supported Data Types

Port	Supported Data Types
Input	Double-precision floating point Single-precision floating point Fixed point (signed and unsigned) Boolean 8, 16, and 32-bit signed integers 8, 16, and 32-bit unsigned integers Enumerated
Output	Double-precision floating point Single-precision floating point Fixed point (signed and unsigned) Boolean 8, 16, and 32-bit signed integers 8, 16, and 32-bit unsigned integers Enumerated